Curling iron



FIG. 1 is a top perspective view of a curling iron showing our new design;

FIG. 2 is a front elevation view thereof.

FIG. 3 is a rear elevation view thereof.

FIG. 4 is a left side elevation thereof.

FIG. 5 is a right side elevation thereof.

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in the drawings illustrate portions of the curling iron and form no part of the claimed design. 

CLAIM The ornamental design for a curling iron, as shown and described. 